Phosphor sheet, light-emitting device having the phosphor sheet and method of manufacturing the same

ABSTRACT

Disclosed herein is a light emitting device including: a substrate; a light emitting diode (LED) chip disposed on the substrate; and a phosphor sheet disposed on an upper portion of the LED chip and including alignment members formed on a lower surface thereof. The alignment members contact the LED chip, such that the phosphor sheet is aligned with the LED chip.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2010-0094299, filed on Sep. 29, 2010, which is hereby incorporated byreference for all purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Exemplary embodiments of the present invention relates to a phosphorsheet, a light-emitting device having the phosphor sheet, and a methodof manufacturing the same.

2. Discussion of the Background

A light-emitting diode (LED) is a semiconductor light-emitting devicethat emits light when electrons and holes are re-combined with eachother in a P-N junction structure, by applying current. LEDs operate ata low voltage and have a long lifespan and low cost characteristics.Conventionally, LEDs have mainly been used in a limited number ofapplications. However, recently, LEDs have been used in variousapplications, such as in display devices, illumination devices, vehiclelights, projectors, or the like, due to the development of an industrialtechnology, particularly, the development of an information displaytechnology and semiconductor technology.

A light-emitting device may implement white light by combining an LEDchip with a phosphor. For example, the light-emitting device mayimplement white light by a combination of a blue LED chip made of asemiconductor component emitting light having a wavelength of 430 to 480nm, and a yellow yttrium aluminum garnet (YAG)-based phosphor capable ofemitting yellow light when excited by the light of the blue LED chip.

Conventional light-emitting devices have mainly used a scheme ofapplying a resin composition, in which a yellow phosphor and an epoxyresin or a silicon resin are mixed, to an upper portion of a blue LEDchip, or sealing the LED chip using the resin composition. However, thequalities of the emitted light are significantly affected by theapplication of a method of applying the phosphor and operatingconditions of the LED chip. In addition, there are many difficulties inreproducing the same white light, luminance is irregular, and colorreproduction is deteriorated, due to a mixing ratio of a phosphor and aresin, thermal instability of this resin, irregular deposition of aphosphor at the time of curing of a resin composition, and the like.

Therefore, instead of a method of molding a resin containing a phosphor,a is method of disposing a layer or a sheet including a phosphor on anupper portion of an LED chip has been recently attempted. However, whenthe phosphor sheet is formed to have the same area as that of the upperportion of the LED chip, light emitted from a side of the LED chip maynot be efficiently incident to the phosphor sheet. When the phosphorsheet is formed to be larger than the upper portion of the LED chip, inorder to solve this problem, it is not easy to align the LED chip andthe phosphor sheet with each other, such that the color of emitted lightis not uniform, due to the misalignment. In addition, when the lightemitted from the LED chip is diffusion-reflected, due to collision withphosphor particles dispersed in an inner portion of the phosphor sheet,back to the LED chip, light emission efficiency is reduced.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide a light-emittingdevice including a phosphor sheet is disposed on an upper surface of alight-emitting diode (LED) chip, the phosphor sheet being aligned toemit uniform white light.

Exemplary embodiments of the present invention provide a light-emittingdevice capable of reducing light that is lost due to internal reflectionfrom phosphor particles in a phosphor sheet.

Additional features of the invention will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention.

According to an exemplary embodiment of the present invention, there isprovided a light emitting device including: a substrate; a lightemitting diode (LED) chip disposed on the substrate; and a phosphorsheet disposed on an upper portion of the LED chip and includingalignment members formed on a lower surface thereof.

According to another exemplary embodiment of the present invention,there is provided a phosphor sheet including a mixture of a phosphor anda resin. The phosphor sheet also including: at least one alignmentmember formed on a lower surface thereof, wherein the alignment membercontacts an LED chip.

According to still another exemplary embodiment of the presentinvention, there is provided a method of manufacturing a light emittingdevice, the method including: disposing at least one LED chip on asubstrate; and adhering a phosphor sheet to an upper portion of the LEDchip, the phosphor sheet including an alignment member formed on a lowersurface thereof, wherein the alignment member is protruded from thelower surface of the phosphor sheet to thereby contact a portion of theLED chip.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a cross-sectional view describing a light-emitting device,according to an exemplary embodiment of the present invention.

FIGS. 2A, 2B, 2C, and 2D are views showing various alignment members isprovided on a phosphor sheet, according to exemplary embodiments of thepresent invention.

FIGS. 3A, 3B, 3C, and 3D are views showing various alignment membersprovided on a phosphor sheet, according exemplary embodiments of thepresent invention,

FIGS. 4, 5, 6, and 7 are cross-sectional views describing light-emittingdevices, according to exemplary embodiments of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which exemplary embodiments of the inventionare shown. This invention may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure is thorough, and will fully convey thescope of the invention to those skilled in the art. In the drawings, thesize and relative sizes of layers and regions may be exaggerated forclarity. Like reference numerals in the drawings denote like elements.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, it can bedirectly on or directly connected to the other element or layer, orintervening elements or layers may be present. In contrast, when anelement is referred to as being “directly on” or “directly connected to”another element or layer, there are no intervening elements or layerspresent.

FIG. 1 is a cross-sectional view of a light-emitting device, accordingto an exemplary embodiment of the present invention. FIGS. 2A to 3D areviews showing various alignment members provided on a phosphor sheet,according to exemplary embodiments of the present invention.

Referring to FIG. 1, the light-emitting device includes a lowersubstrate 10, a light-emitting diode (LED) chip 100, a phosphor sheet 40disposed on an upper portion of the LED chip 100, and an adhesive member30. However, for simplifying the drawing, a detailed configuration ofthe LED chip 100 is not shown.

Here, the lower substrate 10 may be any substrate, as long as the LEDchip 100 may be mounted thereon at a high density. The lower substrate10 may include, for example, alumina, quartz, calcium zirconate,forsterite, SiC, graphite, fused silica, mullite, cordierite, zirconia,beryllia, aluminum nitride, low temperature co-fired ceramic (LTCC), orthe like. However, the lower substrate 10 is not limited thereto. Aceramic may be used as a multi-layer ceramic package (MLP), by formingmetal conductor wiring patterns thereon and using a firing process.

The lower substrate 10 may include patterned electrodes (not shown)formed thereon. The electrodes may include an anode electrode and acathode electrode and may be formed of a highly conductive material,such as copper or aluminum. The anode and cathode electrodes correspondto an n-type electrode (not shown) and a p-type electrode (not shown) ofthe LED chip 100, and are spaced apart from each other for electricalinsulation.

The LED chip 100 is a vertical LED and includes an n-type layer 21, anactive layer 22, and a p-type layer 23. The LED Chip 100 may be formedby growing a nitride semiconductor material on a growth substrate (notshown), through a known deposition process, such as a metal organicchemical vapor deposition (MOCVD) method, a molecular beam epitaxy (MBE)method, or the like. More specifically, the n-type layer 21 and thep-type layer may be formed of a GaN film, and the active layer 22 may beformed of an InGaN film.

The light-emitting diode chip 100 may be, for example, a bluelight-emitting LED chip but is not limited thereto. The light-emittingdiode chip 100 may include a semiconductor component that emits lighthaving a wavelength of 430 to 480 nm. However, an LED chip emittinganother color of light may be used as the LED chip 100, and the presentinvention is not limited to a specific LED chip. Further, aspects of thepresent invention may also be applied to a horizontal LED.

In addition, the phosphor sheet 40 may include a phosphor that isexcited by blue light emitted from the LED chip 100 and that emitsyellow light. However, different phosphors may be used, in accordancewith the color of light emitted by the LED chip 100, so long as whitelight is produced. The phosphor sheet 40 will be described in detailbelow.

The adhesive member 30 is interposed between the LED chip 100 and thephosphor sheet 40, to adhere the LED chip 100 and the phosphor sheet 40to each other. That is, after the adhesive member 30 is applied to anupper portion of the LED chip 100 or a rear surface of the phosphorsheet 40, the phosphor sheet 40 may be adhered directly to the LED chip100.

The adhesive member 30 may include a transparent adhesive, such as anultraviolet (UV) curable resin, a thermosetting resin, a sealant, or thelike. The refractive index of the adhesive member 30 may have a valuebetween a refractive index of the LED chip 100 and a refractive index ofthe phosphor sheet 40, thereby making it possible to reduce the totalinternal reflection of the LED chip 100. Furthermore, although notshown, an outer surface of the phosphor sheet 40 (opposite to a surfaceon which the phosphor sheet 40 is adhered to the adhesive member 30),that is, an emitting surface 41 of the phosphor sheet 40, may beroughened, in order to reduce the total internal reflection of the LEDchip 100. The phosphor sheet 40 may be manufactured in a slurry form, bymixing a phosphor and a resin with each other. The resin may be a resinhaving high hardness and reliability. For example, the resin may be athermosetting resin having transparency, such as, for example, a siliconresin, an epoxy resin, a glass, a glass ceramic, a polyester resin, anacrylic resin, an urethane resin, a nylon resins, a polyamide resin, apolyimide resin, a vinyl chloride resin, a polycarbonate resin, apolyethylene resin, a Teflon resin, a polystyrene resin, a polypropyleneresin, a polyolefin resin, or the like. However, the resin is notlimited thereto.

A single type of phosphor may be included in the resin or a mixture ofmultiple phosphors may be used. As described above, a conventionallight-emitting device is manufactured by burying a blue/near ultravioletLED in an epoxy phosphor mixture, such that the resultant device has lowthermal stability and light stability. On the other hand, the phosphorof the phosphor sheet 40 has excellent thermal stability, lightstability, and luminance.

The present phosphor may be any suitable phosphor for wavelengthconversion. The phosphor may include at least one selected from a groupconsisting of, for example, (Ba, Sr, Ca)₂SiO₄:Eu²⁺, YAG((Y, Gd)₃(Al,Ga)₅O₁₂:Ce³⁺) based phosphor, TAG((Tb, Gd)₃(Al, Ga)₅O₁₂:Ce³⁺) basedphosphor, (Ba, Sr, Ca)₃SiO₅:Eu²⁺, (Ba, Sr, Ca)MgSi₂O₆: Eu²⁺, Mn²⁺, (Ba,Sr, Ca)₃MgSi₂O₈: Eu²⁺, Mn²⁺ and (Ba, Sr, Ca)MgSiO₄: Eu²⁺, Mn²⁺. Thephosphor sheet 40 may have various thicknesses. When the phosphor sheet40 has an excessively thin thickness, it may be difficult to uniformlydistribute the phosphor in an inner portion of the phosphor sheet 40,such that it is difficult to produce white light. On the other hand,when the phosphor sheet 40 has an excessively thick thickness, theluminous intensity (cd) may be reduced. Therefore, it is possible toappropriately adjust a thickness of the phosphor sheet, in considerationof these factors.

The phosphor sheet 40 may be manufactured by press-molding a mixture(slurry) of the resin and the phosphor, in a mold, so as to have a sheetshape as described above. However, the present invention is not limitedthereto. That is, the phosphor sheet 40 may be manufactured by supplyingthe slurry to an extruder and pushing the slurry from the mold by anextrusion molding method. In the alternative, the phosphor sheet 40 maybe manufactured using a doctor blade method. Therefore, the phosphorsheet 40 may be manufactured by any suitable method of forming a sheet.

The phosphor sheet plate may be cut to have a desired size and shapethrough, for example, a sawing or scribing process. That is, thephosphor sheet 40 may be cut at a desired size, so as to be disposed onthe upper portion of the LED chip 100. The cut phosphor sheet 40 may bethen adhered to the upper portion of the LED chip 100.

The phosphor sheet includes an alignment member 50 to align the phosphorsheet 40 and the LED chip 100, in order to dispose the phosphor sheet 40at a correct position on the upper surface of the LED chip 100. That is,at least one alignment member 50 is formed on the rear surface of thephosphor sheet 40, thereby making it possible to properly align the LEDchip 100 and the phosphor sheet 40.

The alignment member 50 may be formed integrally with the phosphor sheet40 at the time of manufacturing of the phosphor sheet 40. Alternatively,a separate alignment member 50 may be formed and then adhered to therear surface of phosphor sheet 40. When the alignment member 50 isformed integrally with the phosphor sheet 40, the alignment member 50may be made of the same material as the phosphor sheet 40. When thealignment member 50 is formed as a separate member, the alignment member50 may be made of a transparent resin, so as not to interfere with thelight emitted from the LED chip 100. The is alignment member 50 contactsthe upper portion of the LED chip 100, when the phosphor sheet 40 ismoved relative to the LED chip 100, to thereby align the phosphor sheet40 on the LED chip 100.

The height or length L of the alignment member 50 from a surface of thephosphor sheet 40 may be shorter than a distance from the upper surfaceof the LED chip 100 to the active layer 22, in order to avoid aphenomenon in which the light emitted from the active layer 22 of theLED chip 100 is interfered with by the alignment member 50. Although thealignment member 50 is shown protruding from the rear surface of thephosphor sheet 40, the alignment member 50 may be formed have variousshapes and may be disposed at various positions, as shown in FIGS. 2 and3. However, the present invention is not limited to the shown shapes andposition.

FIGS. 2A to 3D are plan views showing the rear surface of the phosphorsheet 40, wherein a dotted line indicates a position at which the LEDchip 100 is adhered to the phosphor sheet 40. Referring to FIGS. 2A to3D, the alignment member 50 may be disposed in the vicinity of at leastone edge of the rear surface of the phosphor sheet 40 (See FIGS. 2A to2C and 3A to 3C) or may be formed to be extended along at least one sideof the phosphor sheet 40 (See FIGS. 2D and 3D).

That is, the alignment member 50 may be L-shaped, as shown in FIG. 2A,may be arc-shaped, as shown in FIG. 2B, or may be rectangular as shownin FIGS. 2C and 2D. The alignment member 50 may be formed on the rearsurface of the phosphor sheet 40, adjacent to an edge of the phosphorsheet 40, or may be disposed along one side thereof, to thereby guidethe phosphor sheet 40.

Alternately, as shown in FIGS. 3A to 3D, at least one pair of alignmentis members 50 having the same shape may be formed. Here, a pair ofalignment members 50 may be disposed diagonally, so as to be adjacent toopposing corners of the LED chip 100, as shown in FIGS. 3A to 3C. A pairof alignment members 50 may be disposed on opposing sides of the LEDchip 100, as shown in FIG. 3D, or may be disposed along two adjacentsides of the LED chip 100 (not shown). In addition, two pairs ofalignment members 50 may be formed (not shown). More specifically, eachof the alignment members 50 may have the same shape and may be disposedat corresponding corners or sides of the LED chip 100.

Since the alignment member 50 is formed on the rear surface of thephosphor sheet 40, when the LED chip 100 and the phosphor sheet 40 areadhered to each other by the adhesive member 30, the alignment member 50may guide the position of the phosphor sheet 40, by contacting a portionof the LED chip 100. Therefore, it is possible to prevent themisalignment of the phosphor sheet 40, so that a uniform color of lightis emitted from the LED chip 100.

Referring to FIGS. 4 to 7, light-emitting devices according to otherembodiments of the present invention will be described. However, adescription of the same portion as that of the above-mentionedembodiment will be omitted.

FIG. 4 is a cross-sectional view describing a light-emitting device,according to another embodiment of the present invention. Referring toFIG. 4, the light-emitting device includes a phosphor sheet 140including a reflective member 60 formed thereon.

The reflective member 60 transmits light emitted from the LED chip 100.In addition, the reflective member reflects light emitted from thephosphor sheet 140, thereby increasing light extraction efficiency.

The reflective member 60 may be formed of an insulating material havinga is higher reflectivity than Al or Ag. For example, the reflectivemember may include Si, Ti, Ta, Nb, In, and/or Sn. In addition, thereflective member 60 may be formed by alternately stacking at least twolayers of Si_(x)O_(y)N_(z), Ti_(x)O_(y), Ta_(x)O_(y), and/orNb_(x)O_(y). The reflective member 60 may be a distributed Braggreflector (DBR).

The DBR adjusts the optical thicknesses of a high refractive index layerand a low refractive index layer that are alternately stacked, therebymaking it possible to maximize reflectivity to light having a specificwavelength. Therefore, the DBR of which the reflectivity is optimizedaccording to a wavelength of light generated in the active layer 22 isformed, thereby making it possible to tune the reflective member 60 toreflect, for example, ultraviolet light, visible light, or infraredlight.

The reflective member 60 may be formed on the phosphor sheet 140 in aposition corresponding to a position at which the LED chip 100 isformed. That is, the reflective member 60 is formed to have the samewidth as a width w of the upper surface of the LED chip 100, therebymaking it possible to reduce a material cost. Further, the adhesivemember 30 as well as the reflective member 60 may also be formed to havethe same size and shape as the corresponding surface of the LED chip100.

FIG. 5 is a cross-sectional view of a light-emitting device, accordingto still another exemplary embodiment of the present invention.Referring to FIG. 5, the light-emitting device includes a singlephosphor sheet 240 disposed on upper portions of a plurality of LEDchips 100 a, 100 b, and 100 c. While three LED chips are shown, thepresent invention is not limited to any particular number of LED chips.

Although not shown for simplification of the drawing, the light-emittingdevice may also further include reflective members and adhesive membersthat are formed on a lower portion of the phosphor sheet 240. In thiscase, the reflective members and the adhesive members are formed only atareas corresponding to positions at which the plurality of LED chips 100a, 100 b, and 100 c are formed, thereby making it possible to reduce amaterial costs. In addition, a phosphor dispersed in the phosphor sheet240 may be dispersed only to positions corresponding to the plurality ofLED chips 100 a, 100 b, and 100 c, thereby making it possible to furtherreduce the material costs.

Referring to FIG. 5, the phosphor sheet 240 includes a plurality ofalignment members 50 a, 50 b, and 50 c that are regularly spaced fromeach other. The alignment members 50 a, 50 b, and 50 c may be formed tohave the same shape and size and be disposed at positions correspondingto the LED chips 100 a, 100 b, and 100 c, in the same scheme as shown inFIGS. 2A to 3D. Further, similar to the above-mentioned embodiments, thealignment members 50 a, 50 b, and 50 c may be formed integrally with thephosphor sheet 240 during a process of manufacturing the phosphor sheet240, or may be separately manufactured and then adhered to the phosphorsheet 240.

Although FIG. 5 shows that each of the alignment members 50 a, 50 b, and50 c corresponds to one of the LED chips 100 a, 100 b, and 100 c, in anone-to-one relationship, one or more of the alignment members 50 a, 50b, and 50 c may be omitted, such that the alignment sheet 240 includesless than one alignment member per LED chip. For example, the phosphorsheet 240 may be aligned with the LED chips 100 a, 100 b, and 100 c,even if the phosphor sheet 240 includes only one of the alignmentmembers 50 a, 50 b, and 50 c.

Once the phosphor sheet 240 aligned with and adhered to the LED chips100 a, 100 b, and 100 c, the lower substrate 10 and the phosphor sheet240 are cut to separate the LED chips. An alignment member may not beincluded in at least some of the separated LED chips 100 a, 100 b, and100 c.

That is, a method of manufacturing a light-emitting device, according toan exemplary embodiment of the present invention, a plurality oflight-emitting devices may be simultaneously manufactured, by disposingthe LED chips on the lower substrate 10, aligning the phosphor sheet 240using at least one alignment member 50, adhering the aligned phosphorsheet 240, and then cutting the resultant into individual LED chipunits.

Through this process, it is possible to align the phosphor sheet at adesired position on upper portions of the plurality of LED chips, whilereducing an operations and manufacturing time, as compared to a case inwhich phosphor sheets are disposed on individual LED chips. Accordingly,LED chip units having uniform light emission and low defect rates may beproduced.

FIG. 6A is a cross-sectional view describing a light-emitting device,according to an exemplary embodiment of the present invention. Referringto FIG. 6, in the light-emitting device includes a phosphor sheet 340including an alignment member 50, electrodes 70 extending through thephosphor sheet 340, and an LED chip 100 connected to the electrodes 70.

FIGS. 6B and 6B illustrate top plan views of light-emitting devices thatinclude phosphor sheets 340 similar to that of FIG. 6 a. As shown inFIG. 6B, the phosphor sheet 340 includes openings 41. As shown in FIG.6C, the phosphor sheet 340 includes cutouts 42. Electrodes are disposedwithin the openings 41 and the cutouts 42. Herein, the openings 41 andthe cutouts 42 may be referred to as “electrode exposure parts.”

Referring to FIG. 6A, the LED chip 100 may be, for example, a verticalLED. In this case, one of the electrodes 70 may be an n-type electrodeformed on the upper surface of is the LED chip 100, and a p-typeelectrode (not shown) may be formed on the p-type semiconductor layer23. While two n-type electrodes 70 are shown, in FIG. 6A, inconsideration of an increase in an area of the LED chip 100 or currentdiffusion, only a single n-type electrode may also be formed. Further,the positions or the number of n-type electrodes 70 may be variedaccording to various aspects.

If the LED chip 100 is a horizontal LED, n-type and p-type electrodesmay be formed on the upper surface of the LED chip 100. Generally, eachof a single n-type electrode and a single p-type electrode may be formedon the upper surface of the LED chip 100. However, as an area of the LEDchip increase, the number of electrodes may be changed. However,hereinafter, the vertical LED will be mainly described.

The phosphor sheet 340 may be provided with the electrode exposure parts41 and 42 corresponding to positions and shapes of the n-type electrodes70, in order not to cause damage to the n-type electrodes 70 or bondingwires 80 connected to the n-type electrodes 70, during a process ofadhering the phosphor sheet 340 to the upper surface of the LED chip100.

More specifically, as shown in FIG. 6B, the phosphor sheet 340 may beprovided with the opening 41. Through this configuration, since an uppersurface of the n-type electrode 70 of the LED chip 100 may be exposedthrough the opening 41 formed in the phosphor sheet 340, the bondingwire 80 may be connected to the exposed upper surface of the n-typeelectrode 70. As a result, the bonding wire 80 may be freely connectedto the upper surface of the n-type electrode 70, regardless of how thephosphor sheet 340 is adhered to the LED chip 100. That is, since thebonding wire 80 may be connected to the upper surface of the n-typeelectrode 70 after the phosphor sheet 340 is adhered to the uppersurface of the LED chip 100, wire bonding may be performed withoutcausing damage to the bonding wire 80.

The opening 41 may be formed by irradiating a surface of the phosphorsheet 340 with a laser beam, or be formed by using a punching machine.The opening 41 may also be formed through an additional process, afterthe phosphor sheet 340 is manufactured. In the alternative, the openingsmay be formed when manufacturing the phosphor sheet 340. Therefore, thepresent invention is not limited to a specific method of forming theopening 41.

As shown in FIG. 6C, the cutout 42 is formed at an edge of the phosphorsheet 340. The bonding wire 80 may also be connected to an n-typeelectrode 70 exposed through the cutout 42, after the phosphor sheet 340is adhered to the upper surface of the LED chip 100. However, thephosphor sheet 340 may also be adhered to the upper surface of the LEDchip 100 after the bonding wire 80 is connected to the exposed n-typeelectrode 70. Although two cutouts 42 are shown in FIG. 6C, the presentinvention is not limited thereto. When only a single electrode is formedon the upper portion of the LED chip 100, only one cutout 41 may beformed. In addition, although not shown in the drawing, the reflectivemember 60 shown in FIG. 4 may be formed on the rear surface of thephosphor sheet 340.

The electrode exposure parts are formed in the phosphor sheet, therebymaking it possible to attach the phosphor sheet to the LED chip, withoutcausing damage to the electrode of the LED chip or the bonding wire.

FIG. 7 is a cross-sectional view describing a light-emitting deviceaccording to still another exemplary embodiment of the presentinvention. Referring to FIG. 7, the light-emitting includes atransparent film 90 provided between a phosphor sheet 440 and an LEDchip 100 disposed on a substrate 10.

In order to adhere the phosphor sheet 440 to the LED chip 100, withoutcausing damage to an electrode 70 formed on the upper portion of the LEDchip 100 or a bonding wire 80 connected to the electrode 70, theelectrode exposure parts 41 and/or 42 may also be provided as describedabove.

However, in order to minimize cracking of the phosphor sheet 440,electrode exposure parts are not formed. Instead, the transparent film90 is used to adhere the phosphor sheet 440 to the LED chip 100. Thetransparent film 90 separates the phosphor sheet 340 from the LED chip100. As a result, damage to the electrode 70 and/or the bonding wire 80is prevented, without forming electrode exposure parts in the phosphorsheet 440.

The transparent film 90 is adhered to the upper surface of the LED chip100 by a transparent adhesive member (not shown). The transparent film90 is made of a transparent material, such as a UV curable resin, athermosetting resin, a sealant, or the like. The transparent film 90 andthe phosphor sheet 440 may include the same resin. The phosphor sheet440 is spaced apart from the LED chip 100 by the transparent film 90.

That is, the transparent film 90 is interposed between the LED chip 100and the phosphor sheet 440, such that the phosphor sheet 440 is notadhered directly to the upper portion of the LED chip 100. Thus, theelectrode 70 and/or bonding wire 80 may protected from damage during aprocess of adhering the phosphor sheet 440 to the upper surface of theLED chip 100.

However, a size or a width of the transparent film 90 is disposed on theupper surface of the LED chip 100, except for an area at which theelectrode 70 is formed. The thickness of the transparent film 90 may beadjusted, so as not to cause damage to the bonding wire 80. That is,when the transparent film 90 has an excessively thin thickness, theremay be a risk of causing damage to the bonding wire 80. Therefore athickness of the transparent film 90 may be adjusted in consideration ofa height of the bonding wire 80.

The above-mentioned reflective member 60 may be formed the phosphorsheet 440. Through this configuration, light extraction efficiency maybe increased.

In addition, the phosphor sheet 440 includes an alignment member 50formed on a rear surface thereof. In the case of the present embodiment,the alignment member 50 may guide a position of the phosphor sheet 440while contacting the transparent film 90, rather than the LED chip 100.

According to aspects of the present invention, it is possible to alignthe phosphor sheet at a desired position on the upper portion of the LEDchip, without causing damage to the electrode of the LED chip or thebonding wire connected to the electrode, during the process of adheringthe phosphor sheet to the upper portion of the LED chip.

According to various embodiments of the present invention, an operationof aligning the phosphor sheet at a desired position on an upper surfaceof the LED chip is easily performed, and misalignment of the phosphorsheet is prevented, thereby making it possible to provide a lightemitting device emitting uniform while light.

In addition, according to various embodiments of the present invention,light reflected from the phosphor within the phosphor sheet toward theLED chip is reflected back toward the outside, thereby making itpossible to increase luminance light extraction efficiency of the lightemitting device.

It may be understood by those skilled in the art to which the presentinvention pertains that the present invention may be implemented asother specific forms without changing the spirit or essential featurethereof.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A light emitting device comprising: a substrate; a light emittingdiode (LED) chip disposed on the substrate; and a phosphor sheet havingan upper surface and an opposing lower surface that is disposed on anupper surface of the LED chip, the phosphor sheet comprising analignment member that extends from the lower surface.
 2. The lightemitting device of claim 1, wherein the phosphor sheet comprises two ofthe alignment members.
 3. The light emitting device of claim 2, whereinthe alignment members contact sides of the LED chip.
 4. The lightemitting device of claim 2, wherein the alignment members contactcorners of the LED chip.
 5. The light emitting device of claim 2,wherein the alignment members and the phosphor sheet comprise the samematerial.
 6. The light emitting device of claim 1, wherein the alignmentmember contacts a side or a corner of the LED chip.
 7. The lightemitting device of claim 1, further comprising an adhesive memberinterposed between the phosphor sheet and the LED chip, to adhere thephosphor sheet to the LED chip.
 8. The light emitting device of claim 7,wherein the refractive index of the adhesive member is between therefractive index of a semiconductor layer of the LED chip and therefractive index of the phosphor sheet.
 9. The light emitting device ofclaim 8, wherein the upper surface of the phosphor sheet is roughened.10. The light emitting device of claim 1, further comprising arefractive member disposed between the phosphor sheet and the LED chip,the refractive member comprising alternately stacked insulating layershaving different refractive indices.
 11. The light emitting device ofclaim 10, wherein the reflective member is disposed entirely between theLED chip and the phosphor sheet.
 12. The light emitting device of claim1, further comprising a transparent film disposed between the phosphorsheet and the LED chip, to separate the phosphor sheet from the uppersurface of the LED chip.
 13. The light emitting device of claim 12,wherein the transparent film is adhered to the upper surface of the LEDchip by a transparent adhesive.
 14. The light emitting device of claim1, wherein the phosphor sheet further comprises electrode exposure partsthat expose electrodes formed on the upper surface of the LED chip. 15.A phosphor sheet comprising: a generally planar body comprising amixture of a phosphor and a resin; and an alignment member disposed on alower surface of the body, the alignment member configured to contact alight-emitting diode (LED) chip to align the body and the LED chip. 16.The phosphor sheet of claim 15, wherein the alignment member is disposedadjacent to an edge of the body.
 17. The phosphor sheet of claim 15,wherein the alignment member extends lengthwise along an edge of thebody.
 18. The phosphor sheet of claim 15, wherein the alignment membercomprises the phosphor and the resin.
 19. The phosphor sheet of claim15, further comprising a reflective member disposed on the lower surfaceof the body, the reflective member comprising alternately stackedinsulating layers having different refractive indices.
 20. A method ofmanufacturing a light emitting device, the method comprising: disposinga lower surface of a phosphor sheet on an upper surface of alight-emitting diode (LED) chip disposed on a substrate, the phosphorsheet comprising an alignment member that extends from the lower surfacethereof; aligning the phosphor sheet with the LED chip, by contactingthe LED chip with the alignment member; and fixing the aligned phosphorsheet to the LED chip.
 21. The method of claim 20, wherein: thesubstrate comprises a plurality of the LED chips; the phosphor sheetcomprises a plurality of the alignment members; and the aligning of thephosphor sheet comprises aligning the alignment members with respectiveones of the LED chips.